Direct tissue sampling of diazepam and amitriptyline using mixed-mode SPME fibers: A feasibility study
| Autor: | Ingrid J. Bosman, Steven T.J. Droge, Martien H.F. Graumans, Hester Peltenburg, Joop L. M. Hermens |
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| Rok vydání: | 2016 |
| Předmět: |
Chromatography
Facilitated diffusion medicine.medical_treatment 010401 analytical chemistry Sorption 010501 environmental sciences Solid-phase microextraction 01 natural sciences 0104 chemical sciences Pathology and Forensic Medicine Analytical Chemistry Partition coefficient Matrix (chemical analysis) chemistry.chemical_compound chemistry Materials Chemistry medicine Agarose Fiber Physical and Theoretical Chemistry Law Saline Spectroscopy 0105 earth and related environmental sciences |
| Zdroj: | Forensic Chemistry. 1:51-57 |
| ISSN: | 2468-1709 |
| Popis: | Here, we report on the applicability of the C18/SCX fiber (containing both C18 and strong cation exchange groups) as a direct sampling tool in tissue. An agarose gel model was used as semi-solid tissue surrogate, to mimic changes in matrix tortuosity as expected in tissue. Pork muscle was used as tissue source and was loaded with diazepam or amitriptyline using 24 h incubation in spiked phosphate-buffered saline (PBS). Diazepam is neutral and its behavior is predictable based on the octanol–water partition coefficient (Kow). Amitriptyline is >99% positively charged at pH 7.4, and is likely to behave differently in both agarose gel and tissue compared to neutral compounds. The proposed SPME method yielded detectable fiber concentrations after direct sampling in agarose gel and loaded tissue, including short sampling times and different loading concentrations in tissue. Sorption affinity of both diazepam and amitriptyline is decreased when sampling from agarose gel compared to PBS, due to the presence of different binding groups in agarose. Sorption affinities from tissue are even further decreased compared to agarose gel. This indicates that tissue contains even more binding sites for these compounds compared to agarose gel. Interestingly, for both compounds, equilibration in tissue occurred faster than equilibration in agarose gel or PBS, most likely caused by direct fiber contact or through facilitated transport. Although more research is needed to obtain good quantitative results, these results show that the C18/SCX fiber is a sensitive tool to determine tissue concentrations of neutral and cationic compounds. |
| Databáze: | OpenAIRE |
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